Study On The Rapid Colorimetric Detection Of Oxytetracycline And Tetracycline In Food

Tetracycline antibiotics is a kind of broad-spectrum antibiotics produced by actinomycetes.It is widely used in animal husbandry because of it’s low price and good antibacterial effect.In recent years,with the development of animal husbandry,the use of tetracycline antibiotics in aquaculture has been increasing.Excess tetracycline will enter the human body and threatens human’s health.In this paper,we choose oxytetracycline and tetracycline as the target,established a colorimetric method for the detection of tetracycline antibiotics.Specific research contents are as follows:Detection method for oxytetracycline based on the chlorinated hemoglobin.In this paper,we choose the chlorinated hemoglobin(Hemin)solution as the detection system,TMB and H2O2 were used as substrates.By observing the color change of the product,we established a new colorimetric method for the determination of oxytetracycline(OTC).In this paper,we optimized the relevant factors of the experiment.In the OTC concentration range of 0-30 nM,the linear regression equation is: y=1.04×10-3 C+0.0622.The minimum detection limit is 21.89 nM.The recovery range was between 90%-108% and the relative standard deviation was between 1.39%-4.02%.Detection method for tetracycline based on the chlorinated hemoglobin.In this paper,Hemin was used to detect tetracycline(TET),which was similar to that of OTC detection.In the concentration range of 0-25 n M,the linear regression equation is: y=1.44×10-3 C+0.0811.The minimum detection limit is 15.81 nM.The average recovery of each concentration was 92%-106%,and the relative standard deviation was 0.93%-6.58%.This method has good repeatability.Detection method for tetracycline based on the single-stranded DNA.At first,the single-stranded DNA sequence which is rich in guanine is used to enhance horseradish peroxidase activity of the chlorinated hemoglobin(Hemin),and the oxidation of substrate TMB forms a yellow product.Then,TET added to this system will cause the inhibition of the catalytic activity of Hemin,and the oxydate is blue.The content of tetracycline can be determined by measuring the change of the absorption spectrum of the product.Under the optimal conditions,this method is showing a good linear relationship with the concentration of TET in the range of 10 nM-100 nM,and the linear correlation coefficient is 0.994,and the minimum detection limit is 5.69 nM.Specificity experiments suggest that this method has no significant cross reaction to other antibiotic analogues.The method established in this work has some advantages like good specificity,convenient operation and no need for expensive instruments,so it can be easily used for the detection of OTC and TET residues in dairy products.